1. Field of the Invention
This invention is concerned with a signal blender circuit and device for combining the pickup signals from three or more pickups on one musical instrument (e.g., a guitar) in varying combinations and amplitudes to achieve a composite signal acceptable to the instrument player.
2. Description of the Prior Art
For many musical instruments used to generate signals for electrical amplification it has been conventional practice to employ plural electromagnetic pickups mounted at different locations on the instrument. In electrical guitars, for example, two or three pickups have frequently been employed. The output signals from these pickups are blended to generate a blend signal that is amplified and reproduced by one or more speakers. Because the pickups may not produce outputs of equalized amplitude, and because the performer using the instrument may desire to emphasize the signals from one or more pickups relative to others, the blending procedure is often essential and critical with respect to the musical performance.
The conventional system used to mix signals from two or more pickups consists of a switch which connects the pickups in parallel so as to mix pickups No. 1 and No. 2 or No. 2 and No. 3. The No. 1 and No. 3 pickups are almost never connected together by this switch system. The standard method to mix has used a five position switch of the shorting type. Position No. 1 for the switch uses the output from only pickup No. 1. Switch position No. 3 uses the second pickup alone. Switch position No. 5 has the third pickup by itself. Switch position No. 2 connects the first and second pickups together, thus mixing the two. Position No. 4 of the switch connects pickups two and three together, thus mixing them. The amount of mixing or the percentage of mixing, pickup 1 vs. pickup 2 or pickup 2 vs. pickup 3, is usually fixed at 50/50 and cannot be changed.
A variable resistor system has been used to mix two pickups by connecting each pickup to one end of a variable resistor and connecting the slider to the output to afford a blend signal. This resistive type of mixing makes it possible to vary the blend, but only allows for mixing two pickups. These systems have employed pots that are of conventional construction and can rotate just 270 degrees.